Calculation of the delamination yield index |
Author : Mihail Sima, Mihaela Raluca Condruz, Cristian Stanica |
Abstract | Full Text |
Abstract :This paper presents a numerical simulation model of the delamination process of a laminated
made up of polimerical composite materials ranforced with carbon fibres. Moreover, a set of experimental tests
have been done to check the delamination resistance, and the yield indices have been defined and substantiated
by generalizing the Hashin-Fabric criterion and the hypotheses of the resistance theories based on the
deformation energy and on the distorting energy of the profile. |
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Advanced communication techniques built on integrated automation of experimental test beds |
Author : Andrei Mitru, Constantin Vilcu, Adrian Stoicescu, Claudia Borzea, Cristian Nechifor |
Abstract | Full Text |
Abstract :The paper describes a communication system within industrial environment between central processing units of the experimental test beds and a laboratory server. Execution of such a communication system requires a scientific study of the communication solutions for the test beds and the server system. The paper determines that a server software implementation will be required. During this phase, a server SCADA application and a resources distribution algorithm are required to be developed. The server hosts one SCADA application which is monitoring and controlling the experimental test beds using the communication system. The application displays in real time values for parameters, the screens containing process flow diagrams, states and processing unit control information from experimental test beds. A smart data acquisition is required to be implemented on the server system which is recording the test beds running parameters by generating data files on the server for later analysis. The server is acting as a resources distribution system for all experimental test beds. An algorithm is required to be developed on the experimental server system. The server through the algorithm is capable to associate tasks from a terminal of a test bed to another and has availability to host activities like resources consuming data acquisition and process calculation. Industrial communication security and procedures for monitoring of the server application users are required to be accomplished also. The paper includes test results within industrial environment that determines the performance for both communication system and server. The results are subject of interpretation and provides a model for future experimentation. |
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Data recorder system for maintenance to rotary blade machines - "HolderPPS" |
Author : Filip Niculescu, Constantin Vilcu, Alexandru Gazdac, Claudia Borzea |
Abstract | Full Text |
Abstract :The HolderPPS system presented in this paper falls into the category of recording systems
created for the proactive maintenance of rotary bladed machines. Based on an innovative architecture, the
Holder-type system contributes to machine equipment diagnosis and to early warnings on potential flaws in
the functioning of the machine. The system is able to determine, in real time, the causes of the warnings and
of the emergency stops of the machine, in order to avoid any potential failures, or the rendering inoperative of
the machine. These causes can be established by monitoring the critical parameters of the machine: vibrations,
temperature, and quality of the lubricating oil. As such, data collected and processed on the basis of algorithms
relating to high speed mechanical systems, allow local diagnosis of the current state of the machine, or data
transfer, by remote connection, to a laboratory where an off-line analysis can be performed. |
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Solidification segregation in CMSX-4 superalloy: experiments and simulation prediction |
Author : Gheorghe Matache, Alexandru Paraschiv, Cristian Puscasu, Raluca Condruz |
Abstract | Full Text |
Abstract :The segregation degree of alloying elements during solidification in as-cast CMSX-4 singlecrystal
superalloy was investigated. The elemental partition coefficients calculated using the results of
experimental measurements of local compositions and predicted by thermodynamic calculation in
multicomponent alloys have shown the tendency of the elements to segregate either into the dendrites (W, Re)
or in the interdendritic regions (Al, Ti, and Ta). Among the alloying elements Re has the strongest tendency to
segregate. It was found a good agreement between the experimental and simulation prediction results, as well
as compared with an analytical model. By thermodynamic calculation it was established the influence of
superalloy chemistry on the elemental segregation during solidification. |
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Carbon nanotube and nanoclay based polymeric composites - recent achievements and future development directions |
Author : Mihaela Raluca Condruz, Ionut Sebastian Vintila |
Abstract | Full Text |
Abstract :A literature survey was conducted to determine the trends in polymer composite field. It is
foreseen that the future composite material design will consist in nanocomposites or in hybrid laminates. The
purpose of the nanomaterials integration is to improve the current composite’s properties, like mechanical
properties (tensile strength, interlaminar shear strength, stiffness and impact resistance), thermal and electrical
conductivity and electromagnetic interference resistance, to provide structures with superior characteristics
compared with the structures curently used. |
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Lubrication optimization of a screw compressor used for natural gas |
Author : Victoria Teleaba, Mihaiella Cretu, Radu Mirea |
Abstract | Full Text |
Abstract :Present paper shows the lab tests results for oil samples obtained during the monitoring process
within period 12.2016 – 01.2017 from compressor C4 deployed at Munteni extraction site, which uses PAG
oil. Base characteristics determinations were performed as well as FTIR testing for the samples tapped at 3171
and 3195 working hours before and after the periodical maintenance of the compressor, when 60 more liters of
new oil have been added. The degradation tendency of the oil was assessed. The preliminary conclusions
regarding the degradation of base characteristics, emphasizes a better maintenance of these characteristics
related to the previous used oil. The degradation tendency of the oil is currently under analysis and also it’s
compatibility with polymeric parts of the compressor is assessed. |
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Preliminary results regarding the solution for a gaseous-liquid burner |
Author : Ene Barbu, Andreea Mangra |
Abstract | Full Text |
Abstract :Fuel flexibility is a fundamental attribute of combustion installations that equip turboengines
and heat recovery steam generators of cogenerative groups. Therefore, the main objective of the PN
16.26.01.08 project was the study the thermogasodynamic processes in an afterburner and its interaction with
the turboengine, in order to develop a modern technology of design, manufacturing and testing facilities of
multifuel, gaseous-liquid, afterburner. Research focused on the development of a mono-modular natural gas /
kerosene afterburner, with the possibility to function with natural gas / biofuel obtained from camelina. This
paper presents preliminary results regarding defining the gaseous-liquid afterburner solution, through
numerical modeling, based on the experience gained by National Research and Development Institute for Gas
Turbines COMOTI in the field of turboengines and their exploitation, particularly regarding the 2xST 18
Powerplant from Suplacu de Barcau.The gaseous-liquid afterburner optimal solution will be selected after
completing the numerical simulations and corresponding tests. |
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Optimising low speed dynamic balancing of high speed rotors |
Author : Alexandru Tudorache, Robert Isac, Emilian Toma |
Abstract | Full Text |
Abstract :The research conducted revealed some particularities of the rotors manufactured and/or
assembled at INCD Turbomotoare COMOTI. Different phenomena were encountered, named, and described,
using data recorded while dynamically balancing the rotors, like the phenomena where a rotor spins with
progressively lower amplitude of vibration when increasing the rotation speed (named self-centering
phenomena), to a point where the rotor stabilises, and the phenomena where the heavy point of a specific
correction plane appears to move angularly while balancing at progressively increased speeds (phenomena
usually encountered in the case of flexible rotors). The recorded data was used to create six graphs that give a
clear image of a rotors’ behaviour on a specific range of speeds. After gathering a lot of experimental data,
certain patterns emerged that helped formulate a balancing procedure based on these graphs. The procedure
was tested successfully and it immensely reduced the time required for dynamic balancing with better results
while operating in normal conditions (lower levels of measured vibration of the machinery), at the designed
nominal speed. |
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Management system for power produced by the 37 kW expander-generator group |
Author : Valentin Petrescu, Niculae Toma |
Abstract | Full Text |
Abstract :National Research & Development Institute for Gas Turbines - Comoti has developed a helical
expander - asynchronous electric generator assembly – as well as a test system by tracking the parameters of
thermal, mechanical and electrical processes during common or transitory working regimes, their adjustment
and control in order to ensure maximum security working conditions. The power supplied by the generator
being debited in the COMOTI network. The element of novelty of this electric energy providing assembly
constitutes the use of a helical turbine that works at lower speed than other classical expanders due to the
elimination of the reductor which ensures the connection of the expander to the electric generator. The
monitoring system introduces functional check-ups of the manual and electrical operated elements as well as
the check-up of measuring lines of the analog parameters. The testing was done in the testing stand at COMOTI
premises and it used air as a working agent. The results thus obtained constitute the preliminary data that may
offer the possibility of placing the screw expander - electric generator assembly inside the control and
measuring gas stations. |
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Management system for power produced by the 37 kW expander-generator group |
Author : Valentin Petrescu, Niculae Toma |
Abstract | Full Text |
Abstract :National Research & Development Institute for Gas Turbines - Comoti has developed a helical
expander - asynchronous electric generator assembly – as well as a test system by tracking the parameters of
thermal, mechanical and electrical processes during common or transitory working regimes, their adjustment
and control in order to ensure maximum security working conditions. The power supplied by the generator
being debited in the COMOTI network. The element of novelty of this electric energy providing assembly
constitutes the use of a helical turbine that works at lower speed than other classical expanders due to the
elimination of the reductor which ensures the connection of the expander to the electric generator. The
monitoring system introduces functional check-ups of the manual and electrical operated elements as well as
the check-up of measuring lines of the analog parameters. The testing was done in the testing stand at COMOTI
premises and it used air as a working agent. The results thus obtained constitute the preliminary data that may
offer the possibility of placing the screw expander - electric generator assembly inside the control and
measuring gas stations. |
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A review of the types of heat exchangers usable in closed-cycle turboengines operating at low temperature |
Author : Constantin Sandu, Felix Zavodnic, Mioara Costache |
Abstract | Full Text |
Abstract :The present article is a presentation of several heat exchangers that can be used within closed
cycle turboengines operating at low temperatures. In the case of closed cycle turboengines, the heat exchangers
are used for the transfer of heat to the working fluid following its compression, as well as for the transfer of
heat from the working fluid to an external cooling agent, these actions being necessary for resuming the engine
cycle. The analysis results are useful to INCDT-COMOTI for the prospective development of turboengines
that may work in a closed cycle regime at low temperatures of the engine cycle. |
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